1. Field of the Invention
This invention relates generally to scented materials and more particularly to ceramic type scent carriers.
2. Description of the Prior Art
A great many materials have been used for carrying scents. For example, Carson in U.S. Pat. No. 4,254,179 and Stone in U.S. Pat. No. 4,226,944 both teach processes for impregnating a porous foam product with fragrance. Foams, particularly polyurethane foams, are well adapted as fragrant carriers due to their high porosity and cellular impermeability. Disruption of the cell structure of the foam allows a fragrance to escape through the porous network of the foam.
Another type of scent carrier is taught in U.S. Pat. No. 4,110,261 of Newland which describes a fragrance emitting article having a polymer-petroleum wax composition. Wax based scent carriers differ from foam carriers in that they do not have pores or intersticies which would allow the fragrance to escape. Fragrances are typically released from a waxed based carrier by partially melting it or by scratching its surface.
Yet another approach to scent carriers is described in U.S. Pat. No. 4,293,602 of Coffey. In his patent, Coffey teaches a fragrant ornament consisting of a mixture of natural botanical materials, essential oils, and a fluorocarbon resin binder. The resin binder holds the plant material together and slows the release of the essential oils.
A substantially different approach to scent carrying was taken by Atkinson in U.S. Pat. No. 195,324. In his patent, Atkinson describes a fragrant article made from a porous ceramic soaked in a perfumed oil. The article can be worn as a charm or an ornament such that the perfume is released over a period of time.
Of all of the above cited patents, only Atkinson addresses the problem of applying a scent to a hard, immalleable, and stable material. Obviously, the foam, wax, and resin based scent carriers described above are rather fragile materials and are subject to rapid wear and structural failure. On the other hand, Atkinson's ceramic based scent carrier, if properly fired and cured, can be quite durable and should last many years in normal usage.
Atkinson's article, however, does have certain drawbacks. The rather low absorbtion ability of commercially available ceramic materials means that the articles described by Atkinson cannot hold very much perfume. This, of course, means that his articles will rapidly lose their scent. Furthermore, since commercially available ceramic materials have a moderately high specific gravity of about 1.77, they tend to make rather heavy and clumsy ornaments.